Massively Multiplayer Online Games have become a popular leisure activity and big business. They have also become targets for attacks beyondthe personally motivated cheating attempts. The opportunity to make realmoney by exploiting these virtual worlds have made security a higher priority.Combating the security problems of multiplayer games in software alone is doomed to fail,because the attacker is the player which already controls the system.In this thesis, I investigate security problems in massively mulitplayer online games,and how the technologies collectively known as Trusted Computing can be used to combat these problems.To this end, I have createda new taxonomy, attack-trees and an attack-graph to categories and detail current security problems.These resources are then used when investigatingthe diﬀerent Trusted Computing technologies. Practical problems with theuse these technologies are identiﬁed, and what security problems they cansolve is discussed.The conclusion is that the classic trusted computing technologies wouldsolve the major issues, but require changes to common architecture and cantherefore not be implemented by the game developers alone. The newer,dynamic root of trust based, technologies have great potential as long as thehardware becomes pervasive and a few underlying problems are solved.